How to use GoogleMock in Visual Studio?

Question

This is going to be a self-answered, FAQ-style question. See answer below.

With Visual Studio 2017/2019 it is really easy to set up a new Google Test project and start writing tests (as long as you don't mind using older versions of GoogleTest versions anyway).

But what about using GoogleMock as well? You would think that since Google combined gtest/gmock some time ago that this would just work. Just #include "gmock/gmock.h" and mock away. But no, the GoogleTest NuGet package that is automatically added by the template does not include the gmock folder at all.

Trying to add a second GoogleMock NuGet package causes multiple problems, such as mismatched gtest/gmock versions, overlapping include paths, etc.

Replacing the Microsoft GoogleTest NuGet package with the one from Google causes a link error:

MSVCRTD.lib(exe_main.obj) : error LNK2019: unresolved external symbol _main referenced in function "int __cdecl invoke_main(void)" (?invoke_main@@YAHXZ)

So what is the current recommended (and least painful) way to set up GoogleTest/GoogleMock in Visual Studio? Tests should be able to be discovered, run, and debugged via the Test Explorer.

Ingeringersoll

Answer 1

I've found two ways to set this up: Either compile the whole GoogleTest framework directly into each of the test projects, or create a library project to hold it. Using a library will give faster build times, but you'll need to make sure that compile/link options are the same on the library and the test projects.

Option 1: Compiling GoogleTest Directly in the Test Project

---

1. Create a new project from the Google Test template. Instructions here if needed.
2. Uninstall the Microsoft.googletest.v140.windesktop.msvcstl.static.rt-static NuGet package.
3. Install the latest gmock NuGet package from Google (currently v1.10.0).
4. Add the file gtest_main.cc to the project. It should be in ..\packages\gmock.1.10.0\lib\native\src\gtest\src\

At this point the project should look something like this (if it doesn't, try Unloading and Reloading the project):

The final configuration step is to disable use of Precompiled Headers for the three Google .cc files (Important: Notice the empty fields too).

Option 2: Using GoogleTest in a Static Library Project

---

1. Create a new project from the Static Library (C++) template. Instructions here if needed.
2. Delete all generated .h/.cpp files (pch.h, pch.cpp, framework.h, <ProjectName>.cpp, etc)
3. Install the latest gmock NuGet package from Google (currently v1.10.0).
4. Disable use of Precompiled Headers for the library project (see related pic above).
5. Create a new project from the Google Test template. Instructions here if needed.
6. Uninstall the Microsoft.googletest.v140.windesktop.msvcstl.static.rt-static NuGet package.
7. Add the file gtest_main.cc to the project. It should be in ..\packages\gmock.1.10.0\lib\native\src\gtest\src\
8. Disable use of Precompiled Headers for gtest_main.cc (see related pic above).
9. Add the library project to the test project's Project References.
10. Add ..\packages\gmock.1.10.0\lib\native\include\ to the test project's Include Directories under VC++ Directories

The solution structure should now look something like this:

Writing the Tests

---

Either way, you are now ready to start writing tests using GoogleMock. Add #include "gmock/gmock.h" to the pch.h file:

//
// pch.h
// Header for standard system include files.
//

#pragma once

#include "gtest/gtest.h"
#include "gmock/gmock.h"

Open the generated Test.cpp file and try it.

#include "pch.h"

class MockTest {
public:
    MOCK_METHOD(void, SomeMethod, ());
};

TEST(TestCaseName, TestName) {
    MockTest mock;
    EXPECT_CALL(mock, SomeMethod);
    mock.SomeMethod();
    EXPECT_EQ(1, 1);
    EXPECT_TRUE(true);
}

Ingeringersoll

One thing to watch for if you see hundreds of errors when compiling gmock: It seems that in the vcxproj file's <ImportGroup Label="ExtensionTargets"> section it is vital that the googletest import line comes before gmock. These can get out of order when NuGet packages are removed and added. To fix this simply load up the vcxproj in a text editor and swap the lines. – Juetta

My hero. This solve some other papercut issues I was having with GTest as well. Tyvm for the clear and thorough Q&A – Boleslaw

Excellent, thanks. Some notes: Method1 NuGet works even if you have an older existing test project, and you just want to add gmock to it. You don't need to add gtest_main.cc if you have your own main, for example if you use RUN_ALL_TESTS. I didn't need to disable precompiled headers for the google files. To manage NuGet, right click your project and choose Manage NuGet Packages... – Kendrickkendricks